Electrical receptacle having an improved contact terminal arrangement

ABSTRACT

An improved contact terminal arrangement for an electrical receptacle to provide both back and side wiring thereof. The improved contact terminal arrangement includes providing a threaded aperture in the terminal portion which is generally integral with an electrical contact and providing a clamping plate between the head of the binding screw and the terminal portion.

United States Patent J aconette 1 Sept. 5, 1972 [54] ELECTRICAL RECEPTACLE HAVING AN IMPROVED CONTACT TERMINAL ARRANGEMENT Frank C. Jaconette, Conn.

Inventor: Trumbull,

[73] Assignee: Harvey Hubbell, Incorporated,

Bridgeport, Conn.

Filed: March 3, 1971 App1.No.: 120,648

US. Cl. ..339/217 R, 339/165, 339/249 A, 339/269 Int. Cl. ..IIOlr 13/50 Field of Search ..339/217, 163, 164, 165, 242, 339/249, 263, 266, 269

References Cited UNITED STATES PATENTS 4/1943 Hubbell ..339/113 2/1969 Kulick ..339/249R 782,366 2/1905 Stroud ..151/69 2,136,366 11/1938 Martin ..339/266A FOREIGN PATENTS OR APPLICATIONS 61 11/1913 Netherlands ..339/249 A 692,330 5/1940 Germany ..339/242 900,235 1 l/ 1953 Germany ..339/269 175,831 6/1961 Sweden ..339/249 R Primary Examiner-Marvin A. Champion Assistant Examiner--Robert A. Hafer AttorneyWooster, Davis & Cifelli [57] ABSTRACT An improved contact terminal arrangement for an electrical receptacle to provide both back and side wiring thereof. The improved contact terminal arrangement includes providing a threaded aperture in the terminal portion which is generally integral with an electrical contact and providing a clamping plate between the head of the binding screw and the terminal portion.

2 Claims, 6 Drawing Figures INVENTOR.

ELECTRICAL RECEPTACLE HAVING AN IMPROVED CONTACT TERMINAL ARRANGEMENT BACKGROUND OF THE INVENTION The present invention relates to electrical receptacles, and more particularly, to such receptacles which are designed to be both back and side wired.

l-Ieretofore, electrical receptacles designed for both side and back wiring have usually consisted of the type shown in U.S. Pat. No. 2,317,382 in which a clamping nut is disposed behind the terminal portion within the housing and prevented from rotational movement by the housing. An electric wire may be inserted between the terminal portion and the clamping nut which is moved axially towards the terminal portion upon rotation of the screw for back wiring or the electrical wire may be wrapped about the shank of the screw and pressed against the outer side of the terminal portion by the head of the screw for side wiring. Although the threaded end of the screw is usually staked to prevent inadvertent removal thereof, it, however, can be removed without excessive force thus permitting the clamping nut to be lost within the housing requiring complete dismantling of the receptacle which usually requires removing the receptacle from its mount to allow the screw to be reengaged with the nut. In addition, in such conventional receptacles, the screw usually extends through a blank hole in the terminal portion of the contact which does not insure good electrical connection between the screw and the terminal portion. Furthermore, the housing must be provided with a chamber in which the clamping nut can move axially and must be so formed as to prevent rotational movement of the clamping nut thereby increasing the required size of the receptacle and requiring a more complex molding configuration thereof.

Various attempts have been made to solve at least some of these problems inherent in conventional receptacles. For example, in U.S. Pat. No. 3,314,043 removal of the binding screw thereby losing the clamping nut is prevented by capturing the head of the binding screw by extensions of the molded housing. Side wiring is, however, eliminated by this arrangement and the requirements relating to the size and formation of the clamping nut chamber still remain. In U.S. Pat. No. 3,391,374 compression springs are provided in the chamber behind the clamping nuts to prevent losing the nut if the screw is removed. This arrangement does not reduce the requirements of the formation of the chamber but rather increases them by requiring mounts for the compression springs, and increases the cost of the receptacle by adding to the manufacturing steps and the components required. Another attempt at solving this problem is disclosed in U.S. Pat. No. 2,779,012 in which the clamping nut is fixed at one side to the terminal portion. This solution, however, increases the manufacturing cost by requiring the step of fixing the clamping nut to the terminal portion and does not insure good electrical connection between the back wired electrical wire inasmuch as the clamping nut must move angularly rather than axially. This arrangement limits the space between the clamping nut and the terminal portion for receiving an electrical wire, and the fixed point is subject to failure upon repeated use or undue stress. Thus, the previous attempts have failed to provide simple, practical solutions to these problems.

SUMMARY OF THE INVENTION The present invention has solved these problems by providing an improved contact terminal arrangement including a terminal portion having a threaded aperture which threadably engages the binding screw thereby providing good electrical contact therebetween, and a clamping plate disposed on the binding screw between the head thereof and the terminal portion. This improved contact terminal arrangement allows side wiring by looping an electrical wire around the screw between the plate and the head of the screw and back wiring by inserting the wire between the clamping plate and the terminal portion. By this arrangement good electrical contact is insured, the clamping plate which replaces the clamping nut cannot be lost within the housing upon inadvertent removal of the binding screw and the requirements for providing a chamber within the housing to allow axial movement of the clamping nut and to prevent its rotation are eliminated.

It is, therefore, an object of the present invention to obviate and minimize the problems and disadvantages of previously known contact terminal arrangements of receptacles.

It is a more specific object of the present invention to provide an improved contact terminal arrangement for both back and side wiring of an electrical receptacle which eliminates the problems of lost clamp nuts upon inadvertent removal of the binding screw.

It is another object of the present invention to provide an improved contact terminal arrangement for both back and side wiring of an electrical receptacle which eliminates the requirements imposed by a clamping nut chamber within the housing.

It is still another object of the present invention to provide an improved contact terminal arrangement for side and back wiring of an electrical receptacle which provides good electrical contact between the binding screw and the terminal portion.

BRIEF DESCRIPTION OF THE DRAWINGS These, as well as, other objects and advantages of the present invention, will readily be apparent to those skilled in the art from a perusal of the appended claims, and the following description when read in conjunction with the attached drawings in which:

FIG. 1 is a top plan view of an electrical receptacle incorporating the invention, partially in section, to show the improved contact terminal arrangement of the present invention;

FIG. 2 is a side elevation thereof illustrating the improved contact terminal arrangement;

FIG. 3 is a cross section thereof taken along lines 3- 3 of FIG. 2;

FIG. 4 is a cross section thereof taken along lines 4- 4 of FIG. 2;

FIG. 5 is another cross section thereof taken along lines 5-5 of FIG. 2; and

FIG. 6 is an exploded perspective view of the improved contact terminal arrangement of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, the present invention is illustrated as being part of an otherwise conventional electrical receptacle 10 of the duplex plug type having a housing 12 and a cover 14 both formed from insulating material, and a metal strap 16 for mounting the receptacle in an outlet box. The cover includes the usual openings 18 and 20 for receiving the male electrical plugs and a grounding plug, and the cover is secured to the base by a rivet 22.

Disposed below the openings 18 are contact springs 24 which include integral extensions 26 which are bent away from the contact springs and extend toward the side of the housing where they terminate in terminal portions 28 which extend parallel to the longitudinal side of the receptacle 10. Also as conventional, opposing contact springs 24 at each side of the receptacle are electrically interconnected through an integral median portion, 30 which is generally scored and includes slotted openings 32 for receiving the blade of a screw driver so that it can be removed, if so desired, to isolate the opposite contact springs 24. The housing 12 is provided with openings 34 at each longitudinal side which are adjacent a plurality of seats 36 in which the terminal portions 28 are seated within the housing 12 to allow access to the binding screws 38 which are associated with each of the terminal portions 28.

As described thus far the receptacle is completely conventional. The present invention lies in the unique contact terminal arrangement which will now be described in detail with respect to FIG. 6. The terminal portions 28 are each provided with a threaded aperture 40 in which the binding screws 38 are threadedly engaged. The terminal portions 28 may also include an internally threaded cylindrical extension 41 extending from the threaded aperture 40 to insure a more secure engagement between the binding screws 38 and the terminal portions 28. The clamping plates 42 having a hole 44 therein are disposed on each of the binding screws 38 between the heads 46 thereof and the terminal portions 28. The terminal portions 28 further include outwardly turned flanges 48 stamped therefrom for ensuring good electrical contact between the clamping plates 42 and the terminal portions 28 when the clamping plates 42 are secured against them. The clamping plates 42 may include an inwardly bent top portion 50 for further ensuring a good electrical connection between it and the terminal portion 28. The clamping plate 42 may also include outwardly flared sections 52 at the lower end thereof which when the clamping plate is secured to the terminal portion 28 by means of the binding screws 38 and seated in the housing will be adjacent recesses 54 formed in the lower portion of the housing to facilitate back wiring of the receptacle.

In use the improved contact terminal arrangement of the present invention may be used for either side or back wiring of the receptacle. As illustrated in FIGS. 4 and the contact terminal arrangement of the present invention is seated in the housing and may be back wired by extending the stripped end of a wire 56 through the recess 54 in the housing and between the clamping plate 42 and the terminal portion 28. Altematively, or in addition to back wiring the contact terminal arrangement of the present invention may be side wired by wrapping the curled stripped end of an electrical wire 58 between the head 46 of the binding screw 38 and the clamping plate 42.

As best can be seen in FIG. 5, good electrical contact is preserved between the stamped flanges 48 of the terminal portion 28 and the clamping plate 42 even when an electrical wire is back wired. This ensures good electrical connection between the contact springs and any side wire such as 58. A good electrical connection between the side wire 58 and the terminal portion is further ensured through the binding screw which is in good electrical contact with the terminal portion 28 by means of the threaded engagement therewith.

Thus, an improved contact terminal arrangement for electrical receptacles has been provided which permits both side and back wiring of the receptacle while eliminating the problems inherent in conventional receptacles of this type including eliminating the possibility of losing clamping nuts in the receptacle, maintaining good electrical contact, and eliminating the requirements of the clamping nut chamber in the housing.

It is believed that the many advantages of the present invention will now be apparent to those skilled in the art. It will also be apparent that a number of variations and modifications may be made without departing form the spirit and scope. Accordingly, the foregoing description is to be construed as illustrative only rather than limiting.

What is claimed is:

1. In an electrical receptacle having a housing of insulating material, an electrical contact seated in said housing, a terminal portion integrally formed with said contact and seated in said housing adjacent an opening formed in a side thereof, and a binding screw having a head thereon engageable with said terminal portion and accessible through said opening for holding an electrical wire against said terminal portion, the improvement comprising:

a threaded aperture in said terminal portion for threadably engaging said binding screw,

clamping means disposed between said head of said binding screw and said terminal portion for providing back wiring of said electrical wire between said clamping means and said terminal portion, and side wiring of said electrical wire between said head of said binding screw and said clamping means, said clamping means comprising a plate having an aperture through which said binding screw extends and a flared section at one end, and

said housing including a recessed portion adjacent said flared section to facilitate back wiring of said receptacle.

2. An electrical receptacle comprising:

a housing formed from insulating material;

an electrical contact seated in said housing;

a terminal portion having a threaded aperture therein integrally connected to said contact and seated in said housing adjacent an opening formed in a side thereof;

a binding screw having a head threadably engaged in said threaded aperture and accessible through said opening; and

a clamping plate disposed on said binding screw between said head of said binding screw and said terminal portion;

said clamping plate including a flared portion at one end and said housing including a recessed portion adjacent said flared portion to facilitate back wiring of said receptacle,

said receptacle being adapted to be side wired by securing an electrical wire between said head of said binding screw and said clamping plate and 5 back wired by securing an electrical wire between said clamping plate and said terminal portion. 

1. In an electrical receptacle having a housing of insulating material, an electrical contact seated in said housing, a terminal portion integrally formed with said contact and seated in said housing adjacent an opening formed in a side thereof, and a binding screw having a head thereon engageable with said terminal portion and accessible through said opening for holding an electrical wire against said terminal portion, the improvement comprising: a threaded aperture in said terminal portion for threadably engaging said binding screw, clamping means disposed between said head of said binding screw and said terminal portion for providing back wiring of said electrical wire between said clamping means and said terminal portion, and side wiring of said electrical wire between said head of said binding screw and said clamping means, said clamping means comprising a plate having an aperture through which said binding screw extends and a flared section at one end, and said housing including a recessed portion adjacent said flared section to facilitate back wiring of said receptacle.
 2. An electrical receptacle comprising: a housing formed from insulating material; an electrical contact seated in said housing; a terminal portion having a threaded aperture therein integrally connected to said contact and seated in said housing adjacent an opening formed in a side thereof; a binding screw having a head threadably engaged in said threaded aperture and accessible through said opening; and a clamping plate disposed on said binding screw between said head of said binding screw and said terminal portion; said clamping plate including a flared portion at one end and said housing including a recessed portion adjacent said flared portion to facilitate back wiring of said receptacle, said receptacle being adapted to be side wired by securing an electrical wire between said head of said binding screw and said clamping plate and back wired by securing an electrical wire between said clamping plate and said terminal portion. 